Why would you put in a less powerful engine? You're basically taking a Town Car engine (which is slow already) and making it haul an additional 500 pounds while also fighting the wind coming against the car. Suddenly your "reliable" engine becomes worse than the standard engine, due to the stress of hauling all that weight. Your fuel economy will drop quite a bit compared to the regular engine because your always on the throttle because there's no torque to propel the car from a standstill at a reasonable pace.
You'll need a new wiring harness, and the computer will have to be reprogrammed for the 2 less camshafts and 16 less valves. You're also looking at fuses that'll need to be re-arranged, wires that'll be need to be pulled and resodered; trust me it is way too much work for LESS power (huge emphasis on 60 LESS horsepower and 20lb.ft of torque). You now have a 10-11 second car, not in the quarter mile though.
To put this into performance perspective, a person in a Honda Civic will claim all holy victory for beating a Cobra-powered V8 car to their buddies with park benches on their trunk lids (course, they won't mention it's an SUV).
Just get the 32V and do a simple drop in. Or fix the problem of the engine since you were going to go through the effort of changing out the harnesses and reprogramming anyways.
